for varmints, the 223 is best. Cheap ammo, your gonna be shooting alot. Doesnt heat the barrel fast and if your shootint alot, such as at groundhawgs, thats a BIG concern. Nothing like having to wait for the barrel to cool while those guys laugh at ya. Now thats for varmints or even fox. Now for Coyotes/wolfs Id go for a 22-250 or a 243. Good luck.